The video shows the teenager looking up at the toddler, though the child and the window are out of the camera's frame. The teen looks around, seemingly scanning the scene to see if anyone else is going to help.
Then, the child drops from the second floor. The teen, with his arms up and ready, catches the child.
The little girl's father even gave the young man a reward for saving his daughter's life.
The girl appeared to be OK.